What does filament mean? Botanists define filament as the thread-like stalk that supports an anther of the plant. Together, a filament and an anther make up a stamen, which is the male reproductive part of a flower. Pollen is produced by anthers, and filaments help hold anthers out to make it easier for wind and insects to distribute pollen grains, assisting in the reproduction of the species.
Parts of a Flower
Flowers are the reproductive structures of plants, so their function is to produce offspring. The reproductive process involves the production of both male and female cells and the union of these gametes to form a zygote, which in plants is referred to as a seed.
Flower anthers produce pollen grains, which are the male reproductive cells of flowers. Filament function is to hold the anthers up within the flower, making the pollen more accessible to pollinators and the wind. Flowers come in all sizes, designs and shapes, but generally, filaments extend the anthers up from the base of flowers.
The female reproductive part of the flower is called the pistil. Composed of an ovary, stigma and style, a flower pistil is where pollination occurs. When pollen is transferred from an anther to a receptive stigma – which is the female part that receives the pollen – the process of fertilization may begin.
Diversity of Flowers
The term angiosperm refers to vascular plants that produce flowers, fruits and seeds, and there are about 300,000 species in this group. Widely diverse, their flowers range from microscopic to over a foot wide. Useful to humans for their fragrances, dyes and beauty, flowers are essential structures of angiosperms because they produce seeds for the next generation of plants.
While the purpose of all flowers is the same, each species has its own design and reproductive strategy. Some flowers are perfect, meaning that they contain both stamens and pistils. Others are imperfect, a term that means the flower is missing either stamens or pistil. In other words, some flowers have both male and female reproductive parts, while others produce separate male and female flowers.
In some cases, the male and female flowers are on the same plant, which is called monoecious. Corn is an example of a monoecious plant – the tassels make pollen, and the ears contain the female parts of the plant.
The term dioecious refers to the condition when male and female flowers are produced on separate plants. An example of a dioecious species is the gingko tree.
Unique Flower Filaments
Just as the appearance of each flower species is unique, the internal design of each flower structure is unique, too. In many cases, flower parts are fused together to form different shapes.
When the same type of part is fused together, this is called connation. For instance, the fusion of flower filaments into a tube-like shape is an example of connation. The word for this specific example of connation is monadelphous stamen. Many flowers in the family Malvaceae exhibit monadelphous stamens.
When different types of flower parts are fused together, this is called adnation. For example, in flowers with epipetalous stamens, the stamens are attached to the flower petals. There are several examples of this condition among primrose species.
Filaments also vary in length, even within the same flower. Species with didynamous stamens have two long and two short. A flower with tetradynamous stamens has four long and two short stamens.
Also, the arrangement of the stamens in some species is unusual. In some flowers in the pea family, the stamens and filaments are fused into two groups, which is called diadelphous stamens.
About the Author
Meg Schader is a freelance writer and copyeditor. She holds a Bachelor of Science in agriculture from Cornell University and a Master of Professional Studies in environmental studies from SUNY College of Environmental Science and Forestry. Along with freelancing, she also runs a small farm with her family in Central New York.